The word Key comes from the word Cay and is pronounced the same. Cay is an English is the English version of the word and comes from the Spanish word Cayo.
Is a Key an island or is an Island a key? It can be both, kind of, but not exactly. Both are surrounded by water. An Island is only an Island – land surrounded by water, like Great Britain. But, a Key is a small island, surrounded by water. It is also sandy terrain, with low elevation, that is positioned over Coral Reefs. So that makes it both an Island and a Key.
So an Island can only be an Island. But a Key can be an Island and a Key.
Perhaps that’s one of the multiple reasons that the Keys are so special. Or so weird. Or so especially weird. A unique destination. The Caribbean of the US.